1. Field of the Invention
This invention generally relates to visual systems for flight simulators, and more particularly, to construction of simulated lights on a model board of a camera-model visual display system used with such simulators.
2. State of the Art
One type of visual display system which has gained widespread usage with flight simulators comprises a closed-circuit television system in which a television camera is moved relative to a reduced scale terrain model as the trainee-pilot "flies" the simulated aircraft. The TV camera conveys an image of that portion of the model it is presently viewing to display units surrounding the simulator cockpit.
Models used in such systems are created with painstaking detail to realistically duplicate the landscape visible from an actual aircraft. Often these models include miniature reproductions of airfields or other aircraft landing sites.
To maximize training capability, such models must be useful not only for simulated daylight of flight, but also simulated nighttime operations. In order to realistically simulate nighttime landings, the various lights used at airfields must be simulated on the model.
To simulate airfield lights, the prior art has resorted to small plastic inserts extending through a model board, mirrors mounted on top of the model board and slanted optical fibers. These prior art systems suffer from a number of serious shortcomings including: inadequate brightness along a desired direction, e.g., a simulated glideslope; undesirable variation in color with changes in simulated light intensity; unrealistic appearance; scale discrepancies; and fabrication difficulties.
A model lighting system which overcomes the above enumerated problems is disclosed in a commonly assigned application, Ser. No. 397,147 to R. A. Mecklenborg, filed on Sept. 13, 1973 now U.S. Pat. No. 4,065,859. This system employs individual optical fibers extending perpendicularly through a model board to simulate individual, unidirectional, landing lights. The output end of each of these optical fibers is angled, ground and polished to maximize light projection along a simulated glideslope. For successful simulation, each optical fiber must be mounted in a hole in the model board, so that its output end has a precisely controlled angular orientation and protrusion beyond the model board surface.
A suitable system for so mounting optical fibers in a model board, is described in commonly assigned U.S. Pat. No. 3,903,615 to Martin Dotsko. The fiber mounting scheme of the Dotsko patent employs a keying pin attached with heat shrinkable tubing to each optical fiber and an apertured keying plate affixed to the backside of the model board. The keying pin and plate cooperate to limit rotational and axial movement of the fiber.
Although the approach described in the Dotsko patent has been successfully employed to mount optical fibers in holes in a model board, a need exists for a simpler, less expensive and less tedious method for mounting and maintaining the output ends of optical fibers with precisely controlled protrusions and angular orientations.